Power saving LED lamp from your scrap box.

This circuit is designed by Mr Seetharaman Subramanian and we are very glad to publish it here. In this article he is showing a method to convert a broken/defunct CFL into a LED based power saving light.

This is just a LED lamp circuit that can be operated from the mains voltage. A string of five LED is driven using a capacitive transformer less power supply. In the circuit 0.47uF/400V Polyester capacitor C1 reduces the mains voltage. R1 is a bleeder resistor which drains the stored charge from C1 when the AC input is switched OFF. Resistors R2 and R3 limits the inrush of current when the circuit is switched ON. Diodes D1 to D4 forms a bridge rectifier that rectifies the reduced AC voltage and C2 acts as a filter capacitor. Finally Zener diode D1 provides regulation and the LEDs are driven.

Photos.

Circuit diagram.

Seetharaman’s words about the circuit: I am sending you a table lamp made from defunct energy saver lamp with broken tubes. CFL converted into LED lamp. Most of the components will be available in ones scrap box. Few components available in the CFL PCB also can be used.

Sir, I liked your article ! Rarely people upload such clear concepts; your script, circuit details, explanation of it’s working, all are par excellence. Thanx ! Could you please send me expanation of how exactly a 230 V AC Mains Operated CFL driver circuit works, all with exactly in the manner you have now given for the LED ckt. Also, I want to know if CFL Driver and CFL Ballast are one and the same.

I want to start the business of LED bulbs manufacturing. So i need the yours assist to develop the circuit of LED PCB.
My concept it that we use 6 pieces 0.5 watt SMD for 3 watt LED bulbs. Everything’s going on right but in PCB circuit what kind of capacitors, Diodes and other parts will be working? I want to know in details.

Hello sir, I want to make circuit of led bulb works on 240 v
ac. With high brightness for house use so,please help me
for construction.having 3 to 7 watt power with more lumen about 200 to 500 like 11 w CFL bulb.

You have to use 40 LEDs in series 3 volt 50 MA high bright LEDs to get the same or better illumination. 13 + 14 + 13 in series. Refer to our earlier high bright led project with 24 LEDs. The same circuit can be used for 40 LEDs without modification.

Hi,
I made the 2 nos. 5w LED bulb circuit as suggested by you. It worked well for some time, then one of the bulb went off. I found the both the Resistor 120 ohm was appearing burnt n black. When checked one was not showing continuity. I replaced with a new one. It start working but after few hours again it went off. I checked both the 120 ohm resistor, but it is showing continuity. What is wrong now. Pl advice how to check the circuit. The other one is still working. Also,after power off 4 led is faintly glowing contineously.

Hello Suman Check the 0.47uF 400 volt and C2 for a short. If they are OK 120 ohms 1/2 watt should not change in colour. You can check your LEDs by using 3 volts Lithium disc battery CR2032 with each LED.

Please check the LEDs with DC and find out whether they are healthy. May be your LEDs are rated for 20mA, if so you have to use 274 400 volt capacitor. with 534J you would have passed 50mA hence they would have blown. Check for black spot in the LED through magnifying lens, if there means your leds are blown.

I assembled the circuit is operated well, there two problems,
1. after power off 4 led have glowed faintly , replaced 21v zener but problem did not solved
2. Very high Temperature on R2 & R3
Please give solutions for above

I assembled the circuit is operated well, there two problems,
1. after power off 4 led have glowed faintly , replaced 21v zener but problem did not solved
2. Very high Temperature on R2 & R3
Please give solutions for above
Reply

Hi Sunil it is due to residual charge in 1uF. you can reduce the value of R1 to 100 K it will vanish fast. but this is not going to bother us during operation. R2 and R3 are protective resistances you can use 1 watt to reduce the heat generated. but it is a sacrificial resistance in the event of any high input surge voltage it will burn to protect the other electronics including LEDs. (a slow blow fuse)

Nice little experimental project – but.
Have you measured the power consumed vs the light(lumens)output of this circuit? Could very well be that it is not as efficient as a CFL. Using resisters a capacitor acting as a resister and a shunt regulator (partial short) to drop the line voltage wastes energy as each of these components are consuming power.
The new CFL’s use more efficient switching power supplies to provide the correct voltage for the gas tube, unfortunately this voltage is too high for LED’s , maybe a mod to a CFL power supply is possible, that could be a good project too.

thanks for the circuit, but if you use a resistor in series of LEDs, you have better performance and current will be more adjustable. you should just increase the voltage (20 volt is enough) and then 20-16=4volt divided by 50mA equals 80 ohm resistor above .5 watt.

sir i tried the circuit but only one led glows on touching by tester.
plz rectify the problem.
is it the led or the capacitor or the zener diode.
i have used 6 led’s.all the components are same as mentioned by you above.

Hi Pranav your circuit is not complete check carefully the polarity of the diodes. If with the tester is the circuit is getting completed and the LED is glowing dimly, check the whole circuit for mistakes inter connecting wiring, polarity of zener etc .

I am sorry forgot previous comment I am using this circuit to glow 10 Led. In this i want to replace Transformer because it become very hot AND IT takes more space So can you tell me How to replace transformer
Please send me solution

Sir ,
I am using this circuit to glow 10 Led. In this i want to replace Transformer because it become very hot AND IT takes more space So can you tell me How to replace transformer
Link:-http://sdrv.ms/16c7ipc
Please send me solution
Thanks

this most useful circuit now a days the electrical goods prices are hiked an very high these type of arrangements may give some use full who can use this. it’s simple to make the person who is having basic knowledge about components and electronics.
its good and most use full, cast efective too power saver.

Hi Sweetha The capacitors AC resistance (reactance at 50Hz is used for reducing input voltage to the required level for the LEDs instead of a transformer to step down the voltage. further as the capacitor voltage lags the current by 90deg the power dissipated across it is zero, hence the actual LED consumption can be taken as the power of this LED lamp. Input series resistances are for reducing the inrush current. C2 to smooth the ripple DC. Zener to protect the LEDs against surges in the line.

Sir, i used this ckt with 6 leds 5mm, it seems they doesn’t glow enough as it should be. How can i make them glow to its limit. Can i use something else in place of polyester capacitor, sir pls help me out. Waiting for your reply.
Sir u can mail me at partha_h@hotmail.com

Sir, i used this ckt with 6 leds 5mm, it seems they doesn’t glow enough as it should be. How can i make them glow to its limit. Can i use something else in place of polyester capacitor, sir pls help me out. Waiting for your reply

Dear Sir,
I have made a 44 LEDs,3.6V, 20mA (two rows of 22LEDs) Circuit using same R1 & C1 values, input to the bridge measures 125V ac.But the output of C2(33micro, 160V) is zero though i have connected a 68V zener in reverse across it, what could be wrong? Please help

Dear Sir,
A simple query is about the power consumption of this circuit and also want to confirm will it work OK if kept ON for more than 18 hours continuously daily because I want to use it in place of CFL lamps.

I am impressed. Also saw similar by Nick Vera at http://www.tehhouse.us/electrical/cfledlamp1/index.php He has shown 7 LEDs in picutres but circuit describes 5 or 10 LEDs. Your picture shows 6 but you have shown 5 in the circuit. Will it be ok for 6 LEDs or we have to increase the Zenner to 18 Volts?

Hi PRKASH If capacitor and battery are damaged it is likely LEDs are also damaged. check with 2 pentorch cells in series each led and confirm that they are healthy. If they are healthy use the above circuit delete zener diode, increase C2 voltage rating to 350volts and reduce the value to 10uF. It should be OK.
Hi Biyani seethasub@hotmail.com

Please advise how can I make a 30 lumen output LED set. I have an air-tight enclosure and hence using 5 LED placed within an aluminium reflector to act
as a heat-sink. My input voltage is 6 volts DC that tapers off to about 4.5
volts while in continuous use for about 5 hours.I need to work 10 hours
continuously. Please do advise 1. Type of LED for long life use
2. The Individual Resistance
3. The zener value for reducing the amps
4. Your E-mail ID please and your address
Thank you ,Sir, please do reply. skb

Yes,I have assembled this project ” LED LAMP FROM SCRAP ” after dismentling a useless CFL lamp and is working satisfactorily without any trouble contineously on 13th June,12. I have used 18 volts zener instead of 16V due to non availability in the local market. I have used high power LEDs.
Many Many thanks to your and your team leaders.

Ihave ORKIA make 56 led emergency lamp which is not working when checked up the capacitor blown when i replaced the batteries or down totally insteady of replacing batteries which are are china type i thought of converting entire ckt to stamdard direct 220v regular lamp withought batteries . can I have circuit for the same with component values.

Hi Prasu if you use 3.2volt 50mA hi bright LEDs you can connect upto 100LEDs inseries by linking the 1uF capacitor. and raising 47uF 350volts. With the above circuit you can connect upto maximum 16LEDs. with 47uF 63volts and zener voltage as 56volt. If you use 29LEDs inseries it will be equivallent to 20w cfl use 47uF 100volt use 120volt zener and raise 0.47uF to 0.68uF.

Which LED is used for this circuit.
I need to do this circuit with high brightness, almost giving brightness of 20W CFL tube covering entire room.
Necessary changes in circuit for High brightness and what might be its life span.

Hi sir…. Thanks for this great circuit….. I have made it and it works properly, now i want to make a high brght light with this circuit… So plz tell me that can we use almost 85 leds with this circuit??

Hi Vijay now you are getting switching power supply 12volts which is quite compact in size (1.5″ x 1″ X 1/2 “)and can cater 3 nos 1 watt LEDs in series (use 3.9 ohms 1watt in series). The price is around INR60/- only.

Resp. Sir,
Thank you for your circuits.
But now a days in market we are getting High power 1 watt LEDs, which requires 3.5 volts & 350 milliAmp. current.
So I want to know the circuit based on IC & transistor for driving 1 LED. 3 LED & 9 LEDs.
Please suggest economical circuits.

Hi Harsh you can use up to 12nos of 25mA LEDs with the above circuit. 4 to you will not notice much of a difference in brightness. A 25mA LED can function from 15 to 30mA with very little difference noticeable in the brightness.

Hi Harsh in the defunct bulb 1N4007 4nos and 10uF 400V capacitor are available it can be used. C1 is taking care of dropping the voltage. R2 & R3 are input surge current limitters. C2 is the filter capacitor to avoid flickering of LEDs. Zener is for protecting LEDs against peak surge voltages. the capacitors and the resistances are calculated with the standard formule. V= IR and f = 1 / (2 pi X R X C).

Hi Rambabu yes with 10% tolerance you will have problem.
Hi Nitin you can use two LEDs inseries and three of these in parallel to the 6 volt supply. Current limitting resistances are not required. if your led samples are between 3.2 to 3.6 volts use each LED in series with 56ohms to he supply.

hi,it is always good to have spike protector (mov) in place to protect the circuit from surges. increasing the value of filtering capacitor value can result in smooth operation .
better to have a current limiting resistor after regulator part in series with leds.

Hi Jagan for 1amp the capacitor has to be 14uF 400 volt polyester not electrolytic. will be difficult to get with 7nos of 2.2uF 400 volts polyester it will be expensive and bulky. hence you can use switch mode supply will be efficient compact and economical.

Hi HTOO please calculate the Xc for the capacitor at 50Hz, now add up 2 nos 120 ohms to that each LED is say 3.2 / 0.05A 64ohms add up every thing and use this as a divisor, calculate the current through the LEDs.

Hi Binoy check your mail for my reply. You have to be very careful in choosing the LEDs. use the light for ten minutes disconnect feel the LED temperature if they are quite warm you are driving with higher current reduce capacitor value.

Dear Sir,
i created the circuit in 4 Common pcb’s with 4, 5 & 6 LED’s …. but the problem in all models is the circuit lights up clearly for 3 – 4 hours …. then it become fade…. i changed the components many time including the 1N4007 diodes with several makes…. The same 1N4007 functions in the 24 LED circuit(http://www.circuitstoday.com/mains-operated-led-circuit#comment-31282) clearly….
please explain the possible reasons…. shall i change the 1N4007 to 1A,400V Bridge?

Hi Herman you can use the output 4 leads to light up 11watts 4 pin PL lamp. I have used 18 watt CFL lamp circuit with 11watts PL and it is still working fine. You can swap this other defective CFL where tube is good but electronics have failed.

Hi Seetharaman,
I have a broken CFL, then I take out the electronic ballast (still in good condition). Can I use that electronic ballast to energize LED? Because I see in those schematic DC power supply and other side AC power supply. How can I possible to get safety DC power supply from that things to light on LED? I just want to try recycling that CFL. Thank you.

Hi Soji Disconnect LEDs check the voltage across the Zener it should be around zener’s voltage. if not check D1 to D4 some batch has given us problem as the they were having low PIV of only 50 to 60 volts. ensure that you are using a good company 1N4007. otherwise you should face any problem.

Hi Seetharaman sir, i made the circuit in a conmmon PCB, but the problem is the 50mA (4 leg LED’s, 6 LED’s) with sometimes the Polyster capacitor’s output voltage doesn’t come n if i changed the polarity of the AC it clears but the LED doesn’t lights up. I used the 20volt ZENER. I connected the right way like the displayed diagram, please help…. how can i check the whole circuit with the voltages in every pin… and how can i understand if the electrolytic capacitor is properly working or not…. expecting the reply @ the earliest… Thanks in advance

Hi SEETHARAMAN Sir, i am newbie in electronic, but i am interesting in LED project. I want to ask about your LED lamp circuit, if I add an IC regulator 7812 (this power output is 12 Watts), and I use 10 LED (white super bright each 4.5 Volts DC, 25 mA). I install the LED configuration on parallel with resistor 150 Ohm each LED, can I do that ? Thanks for your answer.

dear seetharaman thank you very much for your brilliant idea.most of such circuit available in the market are without zener diode so it canot be used prolong.Every spike damage leds onebyone.In your circuit led will never damage due to spike.thanks alot.let me know your email id please

Hi Sabitha thanks for pointing. you can use 6 LEDs. The circuit is for 4 stem (2 U tubes)light you can use 5 LEDs with that. latter i switched to 6 stem (4 U Tube)light, which is popular now, hence 6 LEDs are used. you just add one more LED in series and increase Zener diode to 20volts. If you are going to use standard 5mm 25mA LEDs 6nos please reduce the capacitor value to 0.33uF no other changes are required.

Hi SEETHARAMAN sir, i am a newbie in electronics as i am a 1st year diploma student in Polytech. I was in study with LED lighting, and i got your projects in this site. kindly clarify me the above circuit shows 5 LED’s and in the prototype you made shows 6 LED’s… am interesting and collectd the components. Please clarify me the number of LED’s can i use… please send me ur e-mail address too….

Hi Trike sorry, in future this will be taken care.
the following 4 changes are required in the above circuit for 110 volt 60Hz operation.
C1 1.5uF 250V, R1 220K 1/4W, R2 & R3 56 ohms 1/4W other components remain the same.
The approximate power consumption is less than 1 Watt, around 1 unit per month.

A lot of these 230 volt circuits look interesting, but I for one would like to see perhaps a note on converting the input to 110V AC input for American use as well, or an article on converting inputs so that we could adapt these circuits correctly and safely for our own use.